A single chip analog and class D switching mixed mode audio power amplifier using 0.35 µm CMOS process is presented in this paper. It has on-chip power MOSFET's and adopts a novel reverse recovery current free gate control that can reduce EMI noise and current stress of the power MOSFET's. It shows about 0.1% THD at 1 kHz and up to 87% efficiency at 4 Ω BTL at 3.3 V single power supply.

A digital power amplifier is combined with an analog power amplifier via a new ripple feedback filter for high power audio amplifier. Both high fidelity and high efficiency are achieved owing to the proposed filter in combination with a dynamic control of switching frequency. A prototype having a rated power of 2 kW is built for live concert use and tested successfully.

A new analog equalizer supporting 10Base-T central office and remote terminal (Category-3) LAN applications is developed. It provides robust 10 Mbps data transmission (10Base-T) at loop length up to 400 meters. The equalizer with high frequency gain boost capability is controlled automatically by the proposed AZC (Adaptive Zero Control) loop according to cable length. It is implemented using AMS 0.8 µm CMOS technology.

The proposed comparator includes high gain preamplifier with a new swing limiter. It is shown that, for a given unity gain bandwidth, the high gain preamplifier of high output impedance can be made faster than the low gain one if properly combined with a high-speed low-level swing limiter.